Jack hammer

ABSTRACT

A manually actuated Jack Hammer or impacting device includes a cylindrical, relatively thin wall anvil tube having an anvil projecting radially from adjacent its lower end; a cylindrical, relatively thick wall hammer tube telescoped downwardly over the anvil tube for end engagement with the anvil; a recoil spring arranged between upper ends of the tubes; and a pair of operator handles fixed to the hammer tube. The lowerend of the anvil tube may be fitted with an improved tool holder or left open to receive a post or pile to be driven; and one of the operator handles is fitted within an improved lock for selectively holding the tubes in telescoped relationship.

United States Patent [1 1 Deike [451 Feb. 19, 1974 Chamber, Cheyenne, Wyo. part interest to each [22] Filed: Mar. 20, 1972 [21] Appl. No.: 236,103

Related US. Application Data [63] Continuation-impart of Ser. No. 123,787, March 12, 1971, Pat. No. 3,735,822, and a continuation-in-part of Ser. No. 163,696, July 19, 1971, Pat. N0.

[52] 11.8. CI 173/118, 173/121, 173/126 [51] Int. Cl E02d 7/04, B25d H00 [58] Field of Search l73/10l103, 119-121,

173/139, 126, 118; 287/5208; 279/76, 89, 93; 292/l69.l9, 182, DIG. 61

3,050,095 8/1962 Prather 173/91 X 2,998,087 8/1961 Iddings 173/103 X FOREIGN PATENTS OR APPLICATIONS 688,595 2/1940 Germany 292/182 Primary Examiner-Henry C. Sutherland Assistant ExaminerWilliam F. Pate, III Attorney, Agent, or Firm-Bean & Bean [5 7 ABSTRACT A manually actuated Jack Hammer or impacting device includes a cylindrical, relatively thin wall anvil tube having an anvil projecting radially from adjacent its lower end; a cylindrical, relatively thick wall hammer tube telescoped downwardly over the anvil tube for end engagement with the anvil; a recoil spring arranged between upper ends of the tubes; and a pair of operator handles fixed to the hammer tube. The lowerend of the anvil tube may be fitted with an improved tool holder or left open to receive a post or pile to be driven; and one of the operator handles is fitted within an improved lock for selectively holding the tubes in telescoped relationship.

2 Claims, 7 Drawing Figures PAIENTEDFEB 1 W4 3,792,739

SHEET 1 BF 2 PATENTEB FEB] QIQM SHEET 2 BF 2 JACK HAMMER REFERENCE TO RELATED APPLICATIONS The present application is a Continuation-in-Part of U.S. Pat. applications Ser. No. 123,787, filed Mar. 12, 1971, now U.S. Pat. No. 3,735,822, and entitled Manually Actuated Jack Hammer, and U.S. Pat. Ser. No. 163,696, filed July 19, 1971, now U.S. Pat. No. 3,747,690, and entitled Jack Hammer.

SUMMARY OF THE INVENTION The improved Jack Hammer of the present invention includes telescoped cylindrical metal tubes, a sleevelike anvil carried on the lower end of the inner tube and a compression spring arranged between the upper ends of the tubes for rebounding the outer tube after each impact blow of its lower end on the anvil. The inner tube serves as a guide barrel for the outer tube and may have a quick release tool receiving chuck fixed within its bottom and adjacent the anvil or be formed with an opened bottom end to receive a post or pile to be driven. A particularly important feature of the present invention is that the inner tube is not subject to serve impact induced compressive loadings during use and thus may be of relatively thin wall, light weight construction. In this respect, when the inner tube is fitted with a tool holder, the impact loadings are transmitted directly from the anvil to the tool holder,; and when the tool holder is omitted and the inner tube fitted over a post or pile to be driven, impact loadings on the anvil only produce tension stresses in the inner tube. Thus, the only compressive loadings required to be carried by the inner tube are those relatively small loadings occasioned by engagement of the upper end of the inner tube with the rebound compression spring.

The present invention additionally features an improved arrangement for locking the tubes in a telescoped relationship.

DRAWINGS The nature and mode of the present invention will now be more fully described in the following detailed description taken with the accompanying drawings wherein: I

FIG. 1 is an elevational view of a Jack Hammer according to the present invention showing the outer tube lowered into its impact position with parts broken away for purposes of clarity;

FIG. 2 is a view similar to FIG. 1, but showing the outer tube in its raised or recoil position;

FIG. 3 is a view similar to FIG. 2, but showing the Jack Hammer equipped with an anvil tube for driving fence posts;

FIG. 4 is a sectional view taken generally along line 44 in FIG. 2;

FIG. 5 is an enlarged view of the area designated as 55 in FIG. 1, but with parts broken away to show the lock in its locked position;

FIG. 6 is a cross-sectional view taken generally along line 6-6 in FIG. 5; and

FIG. 7 is an enlarged view of the area designated as FIG. 7 in FIG. 1 showing the tool retainer construction in detail.

DETAILED DESCRIPTION Reference is now made more particularly to FIGS. 1

and 2, wherein the Jack Hammer of the present invention is generally designated as 10. Jack Hammer 10 includes a relatively thin wall metal anvil or inner tube 12; a relatively thick wall metal hammer or outer tube 14; an anvil head in the form of a heavy metal sleeve 16 weld afiixed concentrically outwardly of the lower end of anvil tube 12; a coil type compression spring 18- arranged intermediate the upper ends 20 and 22 of tubes 12 and 14, respectively; and an operator handle device 24, which normally serves to permit manipulation of hammer tube 14 and includes a lock device 26 for releasably retaining tubes 12 and 14 in a non-use, fully telescoped relationship. Further, in the construction illustrated in FIGS. 1 and 2, a chuck or holder 28 is weld affixed within the lower end of anvil tube 12 for the purpose of removably carrying a tool 30.

Spring 18 may be suitably retained between tube ends 20 and 22, such as by having its upper end clamped to tube end 22 by means of a nut and bolt assembly 32. Openings 34 and 36 formed in tube ends 20 and 22, respectively, facilitate the flow of air out of and into the chamber or space between the tube ends, during compressions and expansions of spring 18.

Handle device 24 is shown in FIGS. 1, 2 and 46 as including a pair of like constructed handles 40, which are mounted opposite one another on hammer tube 14. Each of handles 40 includes an elongated vertical portion 40a, which is arranged in an essentially parallel relationship to hammer tube 14; and top and bottom end portions 40b, which are bent inwardly relative to vertical portion 40a at angles of approximately and bolt affixed to brackets 42 weld affixed adjacent the extremities of hammer tube 14. Preferably, vertical portions 40a extend substantially the entire length of hammer tube 14 in order to permit an operator to grip the the handles at a convenient level relative to his height and the height of surface on which work is being performed by tool 30. Also, it is preferable to cover at least vertical portions 40a with shock insulating grips 44 formed of rubber or like material.

Each of handles 40 has a metal pipe or tube 46 weld affixed thereto intermediate its upper and lower ends; pipes 46 extending at right angles to their associated handles and terminating immediately adjacent to hammer tube 14. Pipes 46 rest in horizontally disposed, generally V-shaped channels 48 carriedby gusset plates 50; the plates being weld affixed to both channels 48 and hammer tube 14. Bolt devices 52 are received within aligned openings in pipes 46 and channels 48 for the purpose of clamping the pipes and channels together, whereby to provide a shock absorbing connection between the mid-portions of handles 40 and hammer tube 14.

Reference is now made particularly to FIGS. 4-6, wherein lock device 26 is shown as being associated with one of pipes 46 and as including in addition thereto a bolt assembly formed from a stepped metal bolt 54 and a relatively heavy compression spring 56; a relatively light return spring 58; and an operator assembly including a cam 60 and a handle 62. More specifically, bolt 54 is slideably supported within pipe 46 and formed with a reduced diameter or first end portion 64, which is dimensioned to be freely received within hammer tube aperture 66 for frictional engagement with anvil tube 12 for the purpose of releasably retaining tubes 12 and 14 in fully telescoped relationship. Return spring 58, which is arranged concentrically of end portion 64, tends to normally bias bolt 54 to the right as viewed in FIG. 5 in order to remove end portion 64 from engagement with tube 12.

Cam 60 is in the form of a cam tube having an oval cross-sectional configuration and having opposite end portions thereof rotatably supported within and projecting outwardly through aligned wall openings of pipe 46. Handle 62 includes a mounting end portion 62a fixed to extend lengthwise within cam 60, and an operating end portion 62b extending from end portion 62a in a direction transversely of the axis about which cam 60 is rotatably supported by the pipe openings.

As operating end portion 62b is moved into a position where it extends transversely of pipe 46, as shown in FIGS. 1, 5 and 6, cam 60 drives bolt 54 via spring 56 into frictional locking engagement with tube 12 against the bias of spring 58. When bolt 54 is thus engaged with tube 12, the tubes are locked together to facilitate movement of the Jack Hammer from place to place. The tubes may be subsequently freed for relative movement by moving operating end portion 62b into a position wherein it lies essentially parallel to pipe 46, as shown in FIGS. 2 and 4. This releases spring 56 and permits spring 58 to move bolt 54 away from tube 12.

Chuck 28 is best shown in FIG. 7 as including a flaired ended sleeve portion 70 and lower sleeve portion 72, which are weld connected to each other and to tube 12 and anvil head 16. If desired, portions 70 and 72 may be formed from a single heavy hard steel block.

Sleeve portion 70 is formed with a hexagonal hole 74 for slideably receiving the hexagonal shank portion 76 of tool 30, and sleeve portion 72 is dimensioned to freely receive the head 78 of tool for seating engagement with the lower end or shoulder 80 defined by sleeve portion 70. 8

Tool 30 is releasably retained within chuck 28 by means of a restrainer device 82, which is. slideably received with a tube 84 extending at a steep angle upwardly through openings formed in sleeve portion 72 and anvil head 16. Specifically, device 82 includes upper and lower end portions either in the form of the illustrated solid cylinder elements 86 and 88 or in the form of spherical elements, not shown, and a. reduced diameter connecting portion 90, which may be weld affixed to or formed integrally with elements 86 and 88. A pin 92 projects transversely of tube 84 for alternative engagement with elements 86 and 88 in order to limit sliding movement of device 82 within the tube.

To mount tool 30 within chuck 28, it is necessary only to insert shank 76 into hole 74 to cause head 78 to depress the projecting element 88 back into tube 84 sufficiently to permit'the. head to move upwardly for engagement with shoulder 80, whereupon element 88 will be permitted to return to its original position under the influence of gravity wherein it is disposed for retaining engagement with the lower surface of the head. When it is desired to remove the tool from the chuck, it is necessary only to hold the chuck in a horizontal position with tube 84 facing downwardly. Device 82 will then slide under the influence of gravity to remove element 88 from engagement with head 78 and the tool is freed for removal.

In FIG. 3, there is shown a modified form of the invention, wherein the chuck is omitted from anvil tube 12' and the latter dimensioned to slideably receive a post or the like 100 to be driven.

To operate the jack hammer of this invention, it is necessary only to mount the desired tool 30 in chuck 28 of tool receiving anvil tube 12 or to drop anvil tube 12' downwardly over post to be driven. Then, a single operator merely grasps handles 40 at a convenient level, raises the hammer tube 14 to a convenient height and drops it with a downward thrust force whereupon spring 18 will be compressed and the bottom end of hammer tube 14 will deliver a blow to anvil head 16, which in the case of tube 12 transfers the blow directly to the tool. A blow to the anvil head of tube 12' is transferred by the tube to the top of post 100. In either case, the compressed spring 18 then expands to recoil the tube 14 upwardly on the tube 12 or 12' positioning it for the next downward thrust of the operator. A rhythm soon developes enabling the operator to exert maximum impact blows on the tool or post with minimum manual effort.

It will be understood that the tool, post or other work piece being acted upon is never directly engaged by the hammer tube, since the blow from the hammer tube is always transmitted through the anvil head and the anvil tube isolates the hammer tube from the tool, post or work piece.

I claim:

1. An impacting device comprising in combination:

metal inner and outer tubes arranged in a telescoped relationship, said outer tube being formed with a wall aperture intermediate opposite ends thereof; an anvil head secured to a lower end of said inner tube and extending radially outwardly therefrom, said outer tube defining adjacent a lower end thereof a hammer surface arranged to engage said anvil head upon downward reciprocating movement of said outer tube relative to said inner tube; a compression spring disposed between upper ends of said tubes to effect recoil of said hammer surface upwardly away from said anvil head after each blow of said hammer surface thereon; and

handle means secured to said outer tube, said handle means having a pair of gripping portions arranged in a laterally spaced relation and on opposite sides of said outer tube, said handle means includes lock means for releasably retaining said tubes in telescoped relationship, said lock means including a tube portion fixed to extend between said outer tube and one of said gripping portions in alignment with said wall aperture, a locking bolt means slideably supported within said tube portion and including a point and a coil compression spring having adjacent ends arranged in abutting relationship, said bolt having an opposite end portion dimensioned to be freely received within said wall aperture for frictional engagement with said inner tube,-

spring means tending to bias said opposite end portion of said bolt away from engagement with said inner tube, and operator means including cam means and a handle fixed to said cam means, said cam means is a cam tube of oval cross-sectional configuration disposed within said tube portion and having opposite end portions thereof rotatably supported within and projecting outwardly through aligned wall openings of said tube portion whereby said cam tube is supported for rotation about an axis extending transversely of said tube portion between locking and unlocking positions, said cam tube engaging an opposite end of said coil compression spring whereby to drive said opposite end portion of said bolt into engagement with said inner tube against the bias of said spring means when said cam tube is rotated into said locking position and to permit said spring means to bias said opposite end portion of said bolt from engagement with said inner tube when said cam tube is rotated into said unlocking position and said handle includes a mounting end portion fixed to extend lengthwise within said cam tube and an operating end portion joined to said mounting end portion and extending transversely of said axis outwardly of said tube portion, said operating end portion being essentially parallel to said tube portion when said cam tube is in said unlocking position and extending transversely of said tube portion when said cam tube is in said locking position.

2. An impacting device comprising in combination:

metal inner and outer tubes arranged in a telescoped relationship, said tubes being of circular crosssectional configuration and the walls of said inner and outer tubes being characterized as being relatively thin and relatively thick, respectively;

an anvil head secured to a lower end of said inner tube and extending radially outwardly therefrom, said outer tube defining adjacent a lower end thereof a hammer surface arranged to engage said anvil head upon downward reciprocating movement of sid outer tube relative to said inner tube;

a compression spring disposed between upper ends of said tubes to effect recoil of said hammer surface upwardly away from said anvil head after each blow of said hammer surface thereon;

handle means secured to said outer tube, said handle means having a pair of gripping portions arranged in a laterally spaced relation and on opposite sides of said outer tube;

a holder for tools arranged concentrically inwardly of said inner tube anvil, said tools being characterized as having a lower working end portion, an upper shank end portion of non-circular cross-sectional configuration and an intermediate head portion having upper and lower surfaces extending radially outwardly of said working and shank end portions, respectively, said holder defining a cavity having an upper portion configured for slideably receiving said shank end portion in a non-rotating relationship and a lower portion for slideably receiving said head portion and defining a shoulder engageable by said upper surface of said head portion; and

securing means for removably securing said tools within said cavity, said securing means including a passageway sloping downwardly through said anvil and said holder and entering said lower portion of said cavity at a point below said shoulder, a detent supported within said passageway for gravity induced sliding movement to removably position one end of said detent within said cavity for tool retaining engagement with said lower surface of said tool head portion, and means to retain said detent at least partially within said passageway. 

1. An impacting device comprising in combination: metal inner and outer tubes arranged in a telescoped relationship, said outer tube being formed with a wall aperture intermediate opposite ends thereof; an anvil head secured to a lower end of said inner tube and extending radially outwardly therefrom, said outer tube defining adjacent a lower end thereof a hammer surface arranged to engage said anvil head upon downward reciprocating movement of said outer tube relative to said inner tube; a compression spring disposed between upper ends of said tubes to effect recoil of said hammer surface upwardly away from said anvil head after each blow of said hammer surface thereon; and handle means secured to said outer tube, said handle means having a pair of gripping portions arranged in a laterally spaced relation and on opposite sides of said outer tube, said handle means includes lock means for releasably retaining said tubes in telescoped relationship, said lock means including a tube portion fixed to extend between said outer tube and one of said gripping portions in alignment with said wall aperture, a locking bolt means slideably supported within said tube portion and including a point and a coil compression spring having adjacent ends arranged in abutting relationship, said bolt having an opposite end portion dimensioned to be freely received within said wall aperture for frictional engagement with said inner tube, spring means tending to bias said opposite end portion of said bolt away from engagement with said inner tube, and operator means including cam means and a handle fixed to said cam means, said cam means is a cam tube of oval cross-sectional configuration disposed within said tube portion and having opposite end portions thereof rotatably supported within and projecting outwardly through aligned wall openings of said tube portion whereby said cam tube is supported for rotation about an axis extending transversely of said tube portion between locking and unlocking positions, said cam tube engaging an opposite end of said coil compression spring whereby to drive said opposite end portion of said bolt into engagement with said inner tube against the bias of said spring means when said cam tube is rotated into said locking position and to permit said spring means to bias said opposite end portion of said bolt from engagement with said inner tube when said cam tube is rotated into said unlocking position and said handle includes a mounting end portion fixed to extend lengthwise within said cam tube and an operating end portion joined to said mounting end portion and extending transversely of said axis outwardly of said tube portion, said operating end portion being essentially parallel to said tube portion when said cam tube is in said unlocking position and extending transversely of said tube portion when said cam tube is in said locking position.
 2. An impacting device comprising in combination: metal inner and outer tubes arranged in a telescoped relationship, said tubes being of circular cross-sectional configuration and the walls of said inner and outer tubes being characterized as being relatively thin and relatively thick, respectively; an anvil head secured to a lower end Of said inner tube and extending radially outwardly therefrom, said outer tube defining adjacent a lower end thereof a hammer surface arranged to engage said anvil head upon downward reciprocating movement of said outer tube relative to said inner tube; a compression spring disposed between upper ends of said tubes to effect recoil of said hammer surface upwardly away from said anvil head after each blow of said hammer surface thereon; handle means secured to said outer tube, said handle means having a pair of gripping portions arranged in a laterally spaced relation and on opposite sides of said outer tube; a holder for tools arranged concentrically inwardly of said inner tube anvil, said tools being characterized as having a lower working end portion, an upper shank end portion of non-circular cross-sectional configuration and an intermediate head portion having upper and lower surfaces extending radially outwardly of said working and shank end portions, respectively, said holder defining a cavity having an upper portion configured for slideably receiving said shank end portion in a non-rotating relationship and a lower portion for slideably receiving said head portion and defining a shoulder engageable by said upper surface of said head portion; and securing means for removably securing said tools within said cavity, said securing means including a passageway sloping downwardly through said anvil and said holder and entering said lower portion of said cavity at a point below said shoulder, a detent supported within said passageway for gravity induced sliding movement to removably position one end of said detent within said cavity for tool retaining engagement with said lower surface of said tool head portion, and means to retain said detent at least partially within said passageway. 